A relay device can perform high-quality communication even in a wireless mesh network where relay devices are densely arranged and interference of wireless packets is caused. The relay device includes: a representative node determining unit (605) which determines the channel used in its own cluster for intra-cluster communication to be a channel different from the channel used in neighboring cluster for intra-cluster communication, when the communication quality of its own relay device does not meet predetermined quality and no representative node exists among neighboring nodes; a joining and removal notifying unit (607) which allows a neighboring node which is not associated with any cluster to join to its own associated cluster; and a frequency channel changing unit (609) which changes the channel used for intra-cluster communication to the channel determined by the representative node determining unit (605) of the representative node.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A relay device comprising: a representative node determining unit configured to determine, when communication quality of said relay device does not meet predetermined quality and a representative node does not exist among at least one neighboring node, a channel used for intra-cluster communication in a cluster of said relay device to be a channel different from a channel used for intra-cluster communication in a neighboring cluster so that said relay device serves as the representative node, the cluster being formed of relay devices that share a common channel used for data communication, the intra-cluster communication being communication with at least another relay device in a same cluster, the at least one neighboring node being a neighboring relay device which can communicate with said relay device, the representative node being a representative relay device which determines a channel used for the intra-cluster communication; a notifying unit configured to notify the at least another relay device in the cluster of said relay device about the channel determined by said representative node determining unit; a joining unit configured to allow a neighboring node which is not associated with any cluster among the at least one neighboring node to join the cluster of said relay device by causing the neighboring node to use, for the intra-cluster communication, the channel determined by said representative node determining unit, when said relay device is the representative node; and a channel changing unit configured to change the channel used for the intra-cluster communication to the channel determined by said representative node determining unit of the representative node.
2. The relay device according to claim 1 , further comprising: a removing unit configured to remove, from the cluster of said relay device, a relay device having communication quality that does not meet the predetermined quality by prohibiting the relay device from using the channel used for the intra-cluster communication in the cluster of said relay device, the communication quality being quality of communication between the relay device and an every other relay device in the cluster of said relay device.
3. The relay device according to claim 2 , wherein said removing unit is further configured to remove the relay device having the communication quality that does not meet the predetermined quality from the cluster of said relay device by prohibiting the relay device from using the channel used for the intra-cluster communication in the cluster of said relay device, when the relay device requests said relay device to remove the relay device from the cluster of said relay device, the communication quality being quality of the communication between the relay device and the every other relay device in the cluster of said relay device.
4. The relay device according to claim 1 , further comprising: a relay device counting unit configured to count the number of relay devices associated with the cluster of said relay device; and a wireless output adjusting unit configured to reduce a communication output of a communication interface till the number of the relay devices counted by said relay device counting unit reaches a predetermined value.
5. The relay device according to claim 1 , further comprising a first representative node switching unit configured to switch, when said relay device is the representative node, a role of the representative node from said relay device to one of the at least one neighboring node, the one of the at least one neighboring node having communication quality lower than the predetermined quality.
6. The relay device according to claim 5 , further comprising: a communicable node detecting unit configured to detect the at least one neighboring node by transmitting and receiving predetermined data to and from a relay device; and a communication quality measuring unit configured to measure communication quality of the at least one neighboring node detected by said communicable node detecting unit, wherein said first representative node switching unit includes: a communication quality comparing unit configured to specify, when said relay device is the representative node, the one of the at least one neighboring node by comparing the communication quality of the at least one neighboring node measured by said communication quality measuring unit with the predetermined quality, the one of the at least one neighboring node having communication quality lower than the predetermined quality; and a notifying unit configured to notify the at least another relay device in the cluster of said relay device that the role of the representative node is switched from said relay device to the one of the at least one neighboring node specified by said communication quality comparing unit.
7. The relay device according to claim 1 , further comprising: a location information detecting unit configured to detect location information of said relay device; a location information obtaining unit configured to obtain, from the at least another relay device in the cluster of said relay device, location information of the at least another relay device; a centroid location determining unit configured to determine a centroid location of the cluster of said relay device based on the location information of said relay device detected by said location information detecting unit and the location information of the at least another relay device in the cluster of said relay device obtained by said location information obtaining unit; and a second representative node switching unit configured to switch a role of the representative node from said relay device to a relay device located closest to the centroid location among said at least another relay device in the cluster of said relay device, the relay device located closest to the centroid location being specified by comparing the centroid location determined by said centroid location determining unit and the location information of the at least another relay device in the cluster of said relay device obtained by said location information obtaining unit.
8. A relay device comprising: a channel determining unit configured to determine a channel used for intra-cluster communication in a cluster of said relay device to be a channel different from a channel used for intra-cluster communication in a neighboring cluster; a notifying unit configured to notify at least another relay device in a cluster of said relay device about a predetermined channel, the cluster being formed of relay devices that share a common channel used for data communication; a joining unit configured to allow a neighboring node among at least one neighboring node which exists in a neighborhood of the cluster of said relay device to join the cluster of said relay device by causing the neighboring node to use the predetermined channel for intra-cluster communication, the neighboring node being not associated with any cluster and capable of communicating with an every other relay device in the cluster of said relay device in a single hop, the intra-cluster communication being communication with the at least another relay device in a same cluster; and a channel changing unit configured to change the channel used for the intra-cluster communication to the predetermined channel.
9. A relay device comprising: a channel determining unit configured to determine a channel used for intra-cluster communication in a cluster of said relay device to be a channel different from a channel used for intra-cluster communication in a neighboring cluster, the cluster being formed of relay devices that share a common channel used for data communication, the intra-cluster communication being communication with at least another relay device in a same cluster; a notifying unit configured to notify the at least another relay device in the cluster of said relay device about the channel determined by said channel determining unit; a joining unit configured to allow a neighboring node among at least one neighboring node which exists in a neighborhood of the cluster of said relay device to join the cluster of said relay device by causing the neighboring node to use the channel determined by said channel determining unit for the intra-cluster communication, the neighboring node being not associated with any clusters and capable of communicating with an every other relay device in the cluster of said relay device in a single hop; and a channel changing unit configured to change the channel used for the intra-cluster communication to the channel determined by said channel determining unit.
10. A data relay method comprising: determining, when communication quality of the relay device does not meet predetermined quality and a representative node does not exist among at least one neighboring node, a channel used for intra-cluster communication in a cluster of the relay device to be a channel different from a channel used for intra-cluster communication in a neighboring cluster so that the relay device serves as the representative node, the cluster being formed of relay devices that share a common channel used for data communication, the intra-cluster communication being communication with at least another relay device in a same cluster, the at least one neighboring node being a neighboring relay device which can communicate with the relay device, the representative node being a representative relay device which determines a channel used for the intra-cluster communication; notifying the at least another relay device that is associated with the cluster of the relay device about the channel determined in said determining; allowing a neighboring node which is not associated with any cluster among the at least one neighboring node to join the cluster of the relay device by causing the neighboring node to use the channel determined by the representative node determining unit for the intra-cluster communication when the relay device is the representative node; and changing the channel used for the intra-cluster communication to the channel determined in said determining.
11. A non-transitory computer-readable medium comprising a program causing a computer to execute: determining, when communication quality of the relay device does not meet predetermined quality and a representative node does not exist among at least one neighboring node, a channel used for intra-cluster communication in a cluster of the relay device to be a channel different from a channel used for intra-cluster communication in a neighboring cluster so that the relay device serves as the representative node, the cluster being formed of relay devices that share a common channel used for data communication, the intra-cluster communication being communication with at least another relay device in a same cluster, the at least one neighboring node being a neighboring relay device which can communicate with the relay device, the representative node being a representative relay device which determines a channel used for the intra-cluster communication; notifying the at least another relay device that is associated with the cluster of the relay device about the channel determined in said determining; allowing a neighboring node which is not associated with any cluster among the at least one neighboring node to join the cluster of the relay device by causing the neighboring node to use the channel determined by the representative node determining unit for the intra-cluster communication when the relay device is the representative node; and changing the channel used for the intra-cluster communication to the channel determined in said determining.
12. The relay device according to claim 1 , wherein the channel used for the intra-cluster communication in the cluster of said relay device is different from a channel used for inter-cluster communication that is communication with another relay device in a cluster different from the cluster of said relay device.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
July 23, 2009
February 21, 2012
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